Pneumatic cement conveyer



Aug. 23, 1938. w. A. M cCANLES S ET AL 2,127,693

PNEUMATIC CEMENT CONVEYER INVENTORS WILL/AM A. MCCANLESS ROBERT R.HENDERSON ATTORNEY.

Patented Aug. 23, 1938 PATENT OFFICE PNEUMATIC'CEMIENT CONVEYER WilliamA. McCanless and Robert E. Henderson, Merced, Califi, assignors t0Yosemite Portland Cement Corporation, Merced, Calif., a corpora.-

tion of Delaware Application April 16, 1937, Serial No. 137,261

'7 Claims.

This invention relates to pneumatic conveyers for finely divided orpulverulent materials, and particularly to means for continuouslyforcing dry Portland cement powder through conduits or pipes which maybe several hundred feet long, from grinding mills to storage silos, bymeans of air under pressure.

The principal object of the invention is to provide improved apparatusfor the above mentioned purpose whichwill be more effective than priorapparatus used for this purpose. I w

A feature of the invention is to provide a control of the air blastaround the foot of the column of flowing cement.

Another feature is to provide a revolving propeller to continuouslycutoil cement from a compacted air-sealed feed column of cement and throwit outward into the air blast.

A further feature is an independent drive for such a propeller so thatit may be operated at high speed unaffected by the motion of the compacting screw.

A still further feature is the longitudinal adjustability of thepropeller in relation to the compacting screw. I

A further feature is the provision of air booster nozzles adjacent thepropeller to aid in throwing the loosened cement out into the main airstream.

A further feature is the provision of a cylinder around the propellerextending forward of the same into the main air stream.

A still further feature is the provision of perforated air ejectingpipes around the propeller housing and means for adjusting theangularity of the issuing air streams.

Other features and advantages of our invention will appear in thefollowing description and accompanying drawing.

In the drawing:

Figure 1 is a vertical section taken centrally through our improvedpneumatic cement conveying apparatus.

Figure 2 is a cross section of Figure 1 as seen from the line 22thereof.

Figure 3 is an enlarged vertical section of the propeller shaft mountingand associated parts.

Before describing the drawing in detail, it may be stated that broadlyit is old to continuously object of the screw compressed column being toobtain an air seal through which the compressed air released forconveying purposes cannot strike back into the source of supply of thepowder (see Patents Nos. 1,202,088 and 1,258,911) Our apparatus operateson the same principle, but is considerably improved in construction overthe prior apparatus used for this purpose, and gives better control overits operation.

In the drawing 'I is a gravity feed chute as leading the cement outputof one or more grinding mills by gravity to a horizontally disposedcylindrical spiral conveyer box 2 in which is revolvably positioned aspiral conveyer 3 mounted on a hollow shaft 4.

The spiral conveyer fits nicely within its box or cylinder and is hereshown as of double lead or flight construction of gradually decreasingpitch toward the right-hand end so as to gradually compress toward thatend the material being conveyed by it in direction of the arrow from thechute I. The flight of the conveyer may be of triple or single lead ifdesired, though we have found that the double lead seems to operate moreefliciently.

The hollow conveyer shaft 4 passes out of the closed end 5 of the boxthrough a suitable stuffing box or gland 6 and is rotatably supported inone or more bearings as at 'l and has a driving gear 8 secured to it andpreferably a ball or roller thrust collar interposed between the gearhub and the bearing as indicated at 9.

For the purpose of handling ground Portland cement, the spiral conveyermay be from about four to six inches in diameter, and at its forward endthe conveyer box is flared outward as at I0 to a larger size andcontinues forward for about a foot as a larger cylinder I I, whilesurrounding and enclosing this'larger'cylinder II is a rectangular steelcasing I2 closed at its rear end I 3 and welded or otherwise attached tocylinder I I so as to form an air-tight juncture therewith.

Casing I2 is open and flanged at I4 at its forward end and connected toa similarly flanged conical discharge pipe or duct I5 which tapers downto a round outer'end I5 where it connects to the conveyer pipe I6 forconveying the cement to the silo or other point desired.

Within the hollow spiral'conveyer shaft 4 is a propeller drive shaft I!to the inner end of which is attached a bladed propeller I8 for thepurpose of cutting off and throwing a continuous rotary stream of cementfrom the compacted mass at its rear out through the forward end ofcylinder I I intocasing I2.

It is desirable that this propeller be longitudinally adjustable incylinder II to best suit the characteristics of various grades of groundmaterials being handled by the apparatus and to this end it ispreferably provided with the shaft mounting as best shown in Fig. 3, andwherein the propeller shaft II is revolvably supported in oillessbushings I9 fitted within the-outer end of hollow shaft 4 and sealedagainst back pressure of air as by packing 20 held in place as by athreaded self-tightening gland 2 I.

At the outer or rear end of the propeller shaft is a driving pulley 23and its supporting bearing 24. A yoke collar 25 on the propeller shaftbetween bearings I and 24 fitted with a yoked shifting lever 26 providesfor slidi-ngthe propeller shaft longitudinally. The yoke lever may bemoved either way and locked at any'point as by a bolt 21 projecting froma lug 28 on bearing 24 and operating a traveling yoke nut 29 engaged bythe shifting lever 26. By this means the propeller may be adjusted incylinder I I and locked at any position while free to rotate.

To inject air into the rear of casing I2 for forcing the powderedmaterial through and out of cone I5, four perforated pipes 30 forcompressed air are provided in quadrangular arrangement around cylinderII and the perforations 3| are directed forwardly in a manner to makethe air streams converge.

To provide for proper angular adjustment of the perforations, we maygear all of the pipes together for simultaneous rotation as one isturned. Such gearing is shown in Figure 2 at 32. A bearing block 33 ateach corner passes one of the pipes for turning and also revolvablysupports the closed end of the adjacent pipe as indicated.

Each of the pipes is providedwith a suitable sleeve joint 35, to permitturning while each is connected to a service air pressure pipe 35. Ahandle 36,may be provided on any one of the pipes for simultaneouslyturning all of them and the outer end 3'! of the handle crank arm may beused as an indicator against suitable graduated points 38 arranged onthe casing;

Besides the forward ejection of compressed air from perforated pipe 30,we provide several forwardly directed jet pipes 39 extending through thesides of cylinder II just in front of the propeller I8. These jetsreceive their air from a branch airpressure pipe line 40 under separatevalve control 4 I.

By the construction and arrangement described, the powdered materialfrom chute I to be conveyed is, in the operation of the pparatus,tightly compacted in the forward end of the conveyor box 2 againstreverse flow of air, sliced off by the rapidly spinning propeller andthrown forward in cylinder II to be picked up by jets 39, which arepreferably spirally arranged, and given a further spinning motion as itis hurled outward into the main air stream issuing from perforated pipes30 all around cylinder I I and rapidly carried away through conicalsection I5 to the conveying pipe line.

While the apparatus has been developed particularly for the pneumaticconveying of cement, it may be adjusted through the means shown so as tosuccessfully handle many kinds of finely divided materials.

Having thus described our improved pneumatic conveying apparatus, itwill be evident to anyone skilled in the art that minor changes may bemade within the. spirit of the invention and scope of the appendedclaims.

We claim:

1. In a pneumatic conveyer of the character described, a screw conveyeroperatively mounted in a casing and arranged for compacting at itsdischarge end pulverulent material received at the other end, anenlarged casing enclosing the discharge end of the screw conveyercommunicating with a discharge pipe for conveying the material to thedesired point, means for forcing a stream of compressed air from saidenlarged casing directed generally toward said discharge pipe, a rotarypropeller adjacent the discharge end of said screw conveyer arranged forejecting material from the screw conveyer into said enlarged casing fortaking up by said air stream, and means operable -from without thecasings for adjusting said propeller longitudinally of the screwconveyer to regulate its distance from the discharge end thereof.

'2. Ina pneumatic conveyer of the character described, a screw conveyeroperatively mounted in a casing and arranged for compacting at itsdischarge end pulverulent material received at the other end, anenlarged casing enclosing the discharge end of the screw conveyercommunicating with a discharge pipe for conveying the material to thedesired point, a compressed air pipe arranged in said enlarged casingprovided with orifices directed generally toward said discharge pipe, apropeller adjacent the discharge end of said screw conveyer arranged forejecting material from the screw conveyer into said casing for taking upby the air stream from said compressed air pipe, and an extension of thescrew conveyer casing embracing said propeller and projecting forward ofthe same into said enlarged casing.

3. In the construction specified in claim 2, means for ejectingcompressed air into said extension in forwardly directed jets.

4. In the construction specified in claim 2, means for ejectingcompressed air into said extension in forwardly and spirally directedjets.

5. In a pneumatic conveyer of the character described, a screw conveyeroperatively mounted in a casing and arranged for compacting at itsdischarge end pulverulent material received at the other end, anenlarged casing enclosing the discharge end of the screw conveyercommunicating with a discharge pipe for conveying the material to thedesired point, and a plurality of straight compressed air pipes in saidenlarged casing arranged about the discharge end of said screw conveyerand provided with perforations in their side walls directing air jetsforward of said conveyer casing toward said discharge pipe.

6. In a pneumatic conveyer of the character described, a screw conveyeroperatively mounted in a casing and arranged for compacting at itsdischarge end pulverulent material received at the other end, anenlarged cas'mg enclosing the discharge end of the screw conveyercommunicating with a discharge pipe for conveying the material to thedesired point, a plurality of straight compressed air pipes in saidenlarged casing arranged about the discharge end of said screw conveyerand provided with perforations directed generally toward said dischargepipe, and means for turning said compressed air pipes to alter thedirection of air streams from said perforations.

'7. In a pneumatic conveyer of the character described, a screw conveyeroperatively mounted in a casing and arranged for compacting at itsdischarge end pulverulent material received at the other end, anenlarged casing enclosing the disgenerally toward said discharge pipe,and means for simultaneously turning all of said compressed air pipes toalter the direction of air streams from said perforations.

WILLIAM A. MCCANLESS.

ROBERT R. HENDERSON.

